Stoker



Aug. 7, 1951 DODGE 2,563,318

STOKER Filed June 21, 1946 Patented Aug. 7, 1951 NT oFFICE STOKER Adiel Y. Dodge, Rockford, 111. Application June 21, 1946, Serial No. 678,454

- ,3 Claims. 1

This invention relates to stokers and more particularly to means for feeding fuel from a bin'or hopper to the fire box ofa stoker of the type adapted for domestic heating.

In stokers of the type used in domestic heating it has heretofore been customary to feed fuel from the bin or hopper by means of a rotating feed screw mounted in a feed tube. The feed screws are usually supported on bearings at their ends and are driven from one end, thereby creating acute bearing sealing problems and limiting the permissible distance between the bin and fire box. Where a long feed was required it has been customary to use two or more separate screws overlapping at their ends and provided with fuel crossovers.

It is one of the objects of the present invention to provide a stoker in which fuel can 'be fed through substantially any desired distance by a single feeding mechanism.

Another object is to provide a stoker in which bearing and drive mechanism sealing problems are minimized.

Still another object is to provide a stoker in which fuel feed is produced by rotating the feed tube. With this construction the tube can .be supported on external bearings and can be externally connected to its driving mechanism.

A further object is to provide a stoker in which a feed screw extending the full length of the feed tube is not required. Preferably short sections of feed screw are provided adjacent the ends of the tube to insure positive feeding of fuel from the bin and into the fire pot.

A still further object is to provide an intermittent drive for the rotating element of a stoker feed which will yield to prevent damage to the parts in case of jamming and which is balanced to minimize radial bearing loads.

The above and other objects and advantages of the invention will be more readily apparent from the following description when read in connection with the accompanying drawing, in Which- Figure 1 is a top plan view with parts in section of a stoker installation embodying the invention;

Figure 2 is a partial side section on the line 22 of Figure 1 with parts broken away and in section; and

Figure 3 is a section on the line 3-4 of Figure 2.

The stoker installation, as shown in Figure 1, is adapted to feed fuel such as coal, coke, or the like from a hopper or bin indicated generally at [0 to a fire pot indicated generally at II. The

. 2 bin or hopper 10 may be a large permanent storage bin or may, if desired, be a relatively small hopper adapted to be filled periodically with fuel from a storage bin and preferably has its sides at least adjacent the bottom sloping toward the forward central portion of the bottom, as indicated. The fire pot may comprise the usual hopper receiver Hi to receive the fuel around which there is formed a spiral air chamber l3. It will be understood that the sides of the fire pot are formed with openings through which air may flow into the fuel in the fire pot for combustion. Air is supplied to the air chamber [3 by a blower Id driven by an electric motor 15. The usual controls such as thermostats may be provided for controlling operation of the motor [5.

Fuel is conducted from the bin It) to" the fire pot through a cylindrical tube l6 opening'into the lower forward part of the bin and into the fire pot, as shown. The ends of the tube,- as seen in Figure 2, may fit rotatabl'y'i'n sleeve bearings l! in the bin and-the fire pot so that the tube may rotate freely. Since the bearings H are called upon to support very little-weight, they may be made relatively light to guide the ends of the tube and to form an effective seal preventing the escape of dust around the tube ends.

The tube is primarily supported by one or more bearings as indicated at [B engaging the central part of the tube Preferably the tube is driven at a point adjacent the bearing I8- so that any unbalanced driving loads on the tube will be directly absorbed by the bearing I8 thereby'minimizing the loads imposed on the sleeves I1.

The driving mechanism for the tube comprises a one way clutch having an inner race 2| secured to the tube, an outer race 22 and a plurality of gripper members 23 connecting the inner and outer races in one direction of rotation. ,While' any desired type of one way clutch ma -be employed, the clutch as illustrated may beof the type more particularly described and claimed in my Patents Nos. 2,113,722, 2,268,376, 2,307,881, 2,360,481, 2,364,280, 2,365,062 or 2,383,595. As seen in Figure 3, the grippers 23 connect the inner race to the outer race when the outer race is turned counter-clockwise and will permit the outer race to overrun clockwise. The outer race is adapted to be oscillated through a connecting rod 24 connected at one end to one side of the outer race and at its opposite end to one end of a bell crank lever 25 pivoted at 2B. The opposite arm of the bell crank lever is formed with an elongated slot 21 into which one end of a spring link 28 may be adjustably connected. The link 28, as shown, is formed'by a tension spring so that when an excessive tension load is applied thereto the spring will stretch to limit the turning force which can be exerted on the outer race 22. The other end of the link 28 is connected to an eccentric 29 driven by a large gear 3| which is in turn driven by a small gear 32 on the fan and motor shaft.

With this construction, as the eccentric turns it will act through the link 28 to rock the bell crank lever 25 which will reciprocate the connecting rod 24 to oscillate the outer race 22. By adjusting the point of connection of the link 28 to the slot 27 the throw of the connecting rod upon each revolution of the eccentric can be adjusted. As the connecting rod moves up, it will cause the clutch to engage to turn the tube IS in a counter-clockwise direction as viewed in Figure 3, and as the connecting rod moves down, the clutch will overrun. The tube will, therefore, be rotated counterclockwise in a series of relatively short steps.

In the event the tube should be jammed to create an excessive load, the sprin 28 will stretch to limit the force which can be applied to the tube. This spring, therefore, functions as a safety device to prevent damage to the parts. At the same time the spring enables successive impulses to be applied to the tube so that any jamming produced by packing of the fuel or the like will tend to be loosened.

The radial load applied to the tube is at least partially counter balanced by a spring 33 connected to the outer race 22 at a point opposite the connection of the rod 24 thereto. When the outer race is turned clockwise with the clutch overrunning', the spring 33 will be tensioned to store energy, and when the race is turning counterclockwise, the spring will exert a force tending to assist its turning. At this time the spring will be pulling downward on one side of the outer race while the connecting rod 24 is pushing upward on its opposite side so that the radial load may be substantially balanced, thereby reducing the load and wear on the bearing [8.

While fuel will feed successfully through the tube l6 during rotation thereof, it may be preferred in some cases to provide additional means to insure feeding of fuel from the bin into the tube and from the tube into the fire box. As shown, feeding of fuel from the bin to the tube is insured by a short section of worm 34 projecting partially into and secured to the tube. The worm section may be formed by a flat metal strip twisted and which preferably tapers substantially to a point at the end which extends into the bin. With this construction the feeding of fuel from the bin into the tube is insured, and once in the tube the fuel will flow relatively freely therethrough due to the tube rotation.

At the fire pot end of the tube a second short section of worm 35 may be provided projecting into the tube and preferably terminating in a relatively sharp end in the tube. The worm section 35 may be anchored by a cross piece 36 connected thereto and fastened at its ends to the fire 4 pct, as seen in Figure 2. With this construction fuel will be positively forced into the fire pot by the action of the worm section and the tube. To facilitate this effect, the interior of the tube may be roughened or formed with spiral ridges (not shown) which will assist the feeding action.

With the present invention coal or like fuel can be fed through substantial distances with a minimum of mechanism and minimum of friction without requiring special seals for bearings or driving mechanism since the bearings and drive mechanism are outside of the tube.

While one embodiment of the invention has been shown and described in detail, it will be understood that this is illustrative only and is not intended as a definition of the scope of the invention, reference being had for this purpose to the appended claims.

Whatis claimed is:

1. In a stoker, means for feeding fuel comprising a tube, means mounting the tube for rotation, a stationary part adjacent one end of the tube relative to which the tube is rotatable, a feed worm secured to said part and extending axially into said end of the tube, and means for rotating the tube.

2. In a stoker, means for feeding fuel comprising a tube, means mounting the tube for rotation, a stationary part adjacent one end of the tube relative to which the tube is rotatable, a feed worm secured to said part and extending axially into said end of the tube, a worm secured in the tube adjacent its other end, and means for rotating the tube.

3. In a stoker, means for feeding fuel comprising a tube, means mounting the tube for rotation, a stationary part adjacent one end of the tube relative to which the tube is rotatable, a feed worm secured to said part and extending axially into said end of the tube, a worm secured in the tube and projecting from its other end, and means for rotating the tube.

ADIEL Y. DODGE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 311,052 Anderson Jan. 20, 1885 371,609 Marr Oct. 18, 1887 570,978 Brown Nov. 10, 1896 887,785 Gauntt May 19, 1908 895,764 Jones Aug. 11, 1908 1,050,171 Riblet Jan. 14, 1913 1,324,145 Davidson Dec. 9, 1919 1,371,498 Lower Mar. 15, 1921 1,818,807 Mann Aug. 11, 1931 1,850,428 Waechter Mar. 22, 1932 1,921,253 Greene Aug. 8, 1933 2,143,834 Mosshart Jan. 10, 1939 2,146,198 Ward Feb. 7, 1939 2,151,575 Ward Mar. 21, 1939 2,224,991 Schweickart etal. Dec. 17, 1940 

